The art has employed various aqueous solutions of polymeric materials which can be gelled by radiation to form hydrogels. U.S. Pat. No. 5,143,071 lists a number of such hydrogels and specifically discloses polyvinyl pyrrolidone and polyethylene oxide hydrogels formed from aqueous solutions which are cross-linked by radiation dosages of 0.5 to 4.5 Mrads.
The prior art also shows sterile adhesive gel-foil packages made by a process that entails forming an aqueous polymer mixture into a hydrogel, subjecting the hydrogel to radiation to form a partially cross-linked hydrogel; forming the cross-linked hydrogel into sheets; applying a foil to each side of the cross-linked hydrogel to provide a package, and subjecting the resulting package to radiation to sterilize the hydrogel. Although the method of prior art produces sterile adhesive, hydrogel packaged product, the numerous steps required generates considerable processing expense.
A need therefore exists for methods which overcome the disadvantages of the prior art while providing a hydrogel packaged product that has acceptable properties and sterility.